Revival of Nuclear Arms Race: US Conducts New Underground Nuclear Tests
...Since 2010, the U.S. has shot off three subcritical tests and has plans in late 2012 for Pollux, a first-of-a-kind demonstration combining a scaled subcritical experiment with plutonium-239. Pollux is called a subcritical nuclear experiment because it will be held underground and use larger-than-normal (but nevertheless small) amounts of plutonium-239 fuel than used in ordinary hydrodynamic tests. However, it is the first such scaled subcritical test by the U.S. because it will involve a scale model of a warhead primary (using plutonium-239 nuclear material). This is provocative because Pollux will be the closest thing to a full-scale nuclear test that the U.S. has carried out since its last nuclear explosion 20 years ago. (Read more in NNSA Keeps Conducting Nuclear Tests and Mentioning Them Well After the Fact)...
http://www.globalresearch.ca/revival-of-nuclear-arms-race-us-conduct-new-underground-nuclear-tests/